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Publication Abstract from PubMed

Bacteriophage PhiKZ (PhiKZ) is the founding member of a family of giant bacterial viruses. It has potential as a therapeutic as its host, Pseudomonas aeruginosa, kills tens of thousands of people worldwide each year. PhiKZ infection is independent of the host transcriptional apparatus; the virus forms a "nucleus", producing a proteinaceous barrier around the PhiKZ genome that excludes the host immune systems. It expresses its own non-canonical multi-subunit non-virion RNA polymerase (nvRNAP), which is imported into its "nucleus" to transcribe viral genes. The PhiKZ nvRNAP is formed by four polypeptides representing homologues of the eubacterial beta/beta' subunits, and a fifth that is likely to have evolved from an ancestral homologue to sigma-factor. We have resolved the structure of the PhiKZ nvRNAP initiating transcription from its cognate promoter, p119L, including previously disordered regions. Our results shed light on the similarities and differences between PhiKZ nvRNAP mechanisms of transcription and those of canonical eubacterial RNAPs and the related non-canonical nvRNAP of bacteriophage AR9.

Structure of the Bacteriophage PhiKZ Non-virion RNA Polymerase Transcribing from its Promoter p119L.,de Martin Garrido N, Chen CS, Ramlaul K, Aylett CHS, Yakunina M J Mol Biol. 2024 Jul 17;436(18):168713. doi: 10.1016/j.jmb.2024.168713. PMID:39029888^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.